The most common ingredients of a Greek Salad are: Whole tomatoes (cut in wedges), sliced cucumbers (peeled), sliced green bell peppers, sliced onions, Kalamon olives and traditional feta cheese (in a big slice). Mix all the ingredients together in a bowl and add salt, oregano and extra virgin olive oil for dressing.
Of course you can adjust Greek salad according to the flavors you prefer. Keep in mind that this is a very simple salad to make, that is why the quality of the ingredients is critical.
When the salad is finished, you can dip a chunk of bread in the leftover extra virgin olive oil (which will be mixed with the juices from the tomato and crumbles of the feta cheese).